Boat paddle 7mm Mag at the age of 13. It took many rounds of .22 to beat that flinch. And to this day I will not own a 7mm or a 300wm. I probably should though
The only magnum I've ever shot is a 7mm. However, to go along with the theme of boat paddles, I used a Ruger M77 .30-06 boat paddle. That thing kicked worse than a rented mule. I'm in the same boat (pun not intended) that it took many smaller rounds to re-learn not to flinch.
